The present invention relates to an oil tool coupling and decoupling apparatus; more specifically, to an apparatus used for making up or breaking the connection between a downhole tool, such as a drill bit or stabilizer, and the drill string to which either is connected.
In the process of drilling, xe2x80x9ctrippingxe2x80x9d drill pipe into and out of the bore hole primarily requires repetitive connecting and disconnecting of the tubular members, but also less frequently requires repetitive connecting and disconnecting of stabilizers to a tubular drill string, and repetitive connecting and disconnecting the bit from the terminal end of the drill string. Historically, these connections were made by rig personnel moving a set of power wrenches or tongs onto the rig floor to engage the drill pipe and apply torque against the pipe as it was held fixed in location by the rotary table or the topdrive unit. Other devices, referred to as bitbreakers by those in the art, included a fixed metal plate, having the profile of the bit that was attached to the rotary table. Modern drilling rig rental rates dictate that this coupling/decoupling process be performed quickly to minimize the day rental charges for the drilling rig. Various forms of automated machinery have been proposed over the years for moving power tongs into and out of engagement with the drill string to perform these services. None, so far as known to applicant, combine the benefits of the bitbreaker with the automated features of the automated wrenches or tongs.
One form of automated wrenches or tongs moves an apparatus on a track into engagement with the drill string. These units move into engagement and automatically spin the tubular members to make up the joint, then torque the pipe to its make-up torque; or, break-out the pipe, then spin out the tubular member to complete disengagement. These units are heavy weighing in excess of 5,000 kg, require drive tracks or rails and are expensive.
As previously noted, so far as known to applicant, none of the automatic tong devices permitted the coupling or decoupling of stabilizers and bits to or from the drill string. These actions have historically been accomplished by pulling the drill string out of the well bore and manually engaging the tubular joint to be operated with a set of tongs, which are manipulated onto the rig floor by rig personnel. Applicant has devised tools for both spinning the drill string while holding a lower portion to make-up the tool joint, which also tightens the joint to operating torque after makeup. See for example, U.S. Pat. No. 6,212,976; International Publication WO 99/10130, PCT application number PCT/US98/17868; and U.S. Pat. No. 5,351,767; all of which are hereby incorporated herein by reference in their entireties as if copied verbatim herein. The present invention permits the applicant""s existing tools, which spins and/or torque the drill string, to be used to automatically add and remove either stabilizers and drill bits on the drill string. This operation may be accomplished quickly and easily without additional equipment being moved onto the overcrowded rig floor. The apparatus may be suspended by conventional support means that permit the ready movement of the device out of the way of other rig operations.
The present invention is a wrench apparatus having utility to make up and break out a connection between a drill bit or a stabilizer and the drill string. The apparatus comprises an upper assembly having a gripper which is capable of gripping the drill string and a lower assembly which is capable of gripping the drill bit or stabilizer and a torque applicator for turning the upper gripping means and the lower gripping means in selectively opposite directions.
In one aspect, the present invention provides a wrench for make up and break out of a connection between a drill bit or stabilizer having a non-circular cross section and a drill pipe joint disposed along an upright axis. The wrench has an upper assembly comprising a first pipe gripper operable along an angle transverse to the upright axis for holding the drill pipe joint against rotation about the upright axis with respect to the upper assembly. A lower assembly depends from the upper assembly and comprises a drill bit- or stabilizer-receiving member having a non-circular opening matching the cross section of the drill bit or stabilizer for securing the drill bit or stabilizer against rotation about the upright axis with respect to the lower assembly. The lower assembly is rotatably secured with respect to the upper assembly to allow rotation of the upper and lower assemblies with respect to each other about the upright axis. A torque applicator is secured to the upper and lower assemblies for rotating the upper and lower assemblies with respect to each other. A lateral gate opening can be formed in the upper assembly for receiving the drill pipe joint in the pipe gripper.
The wrench preferably also includes a spinner yieldably mounted on the upper assembly for rotating the drill pipe joint about the upright axis with respect to the lower assembly. Springs can be provided between the upper assembly and the spinner. The lower assembly can include a housing for a second pipe gripper operable along an angle transverse to the upright axis for holding a drill pipe joint against rotation about the upright axis with respect to the lower assembly, and a lateral gate opening formed in the housing for receiving a drill pipe joint in the second pipe gripper.
The pipe gripper is preferably a jaw assembly. The jaw assembly can include a housing, a seating jaw and an opposed locking jaw movable toward the seating jaw along an operating axis of the jaw assembly at a transverse angle to the upright axis for securing the drill pipe joint between the jaws.
The drill bit- or stabilizer-receiving member is preferably supported by torque stabilizers removably supported from the housing in torque transmitting relation thereto. The opening is preferably formed in a transverse plate securely attached to the torque stabilizers. The transverse plate preferably has left and right sections hingedly connected at one side of the opening and lockable at an opposite side of the opening. The drill bit- or stabilizer-receiving member can include a drill bit lock secured to the transverse plate and movable into and from locking relation with the drill bit or stabilizer.
The vertical support is preferably movable transversely with respect to the upright axis between a first position wherein the pipe gripper is aligned with a drill string of a drilling rig and a second position disposed away from the drill string.
In another aspect, the present invention provides a method for breaking out a connection between a drill bit or stabilizer and a drill pipe section having a complementary threaded coupling. The method includes the steps of:
(a) positioning the drill bit or stabilizer in the opening of the drill bit- or stabilizer-receiving member of the wrench described above to secure the drill bit or stabilizer against rotation with respect to the lower assembly;
(b) inserting the drill pipe section through the lateral gate and into alignment with the pipe gripper in the upper assembly;
(c) holding the drill pipe section in the pipe gripper against rotation with respect to the upper assembly;
(d) actuating the torque applicator to rotate the upper assembly with respect to the lower assembly and loosen the connection.
The method can also include the steps of releasing the pipe gripper and spinning the drill pipe, while continuing to secure the drill bit or stabilizer against rotation with respect to the lower assembly, to disconnect the drill pipe from the drill bit or stabilizer.
In a further aspect, the present invention provides a method for making up a connection between a drill bit or stabilizer and a drill pipe section having a complementary threaded coupling. The method includes the steps of:
(a) positioning the drill bit or stabilizer in the opening of the drill bit- or stabilizer-receiving member of the wrench described above to secure the drill bit or stabilizer against rotation with respect to the lower assembly;
(b) engaging a lower end of the drill pipe section in the drill bit or stabilizer and spinning the drill pipe with respect to the lower assembly to shoulder the connection between the drill pipe and the drill bit or stabilizer;
(c) engaging the pipe gripper in the upper assembly to hold the drill pipe section in the pipe gripper against rotation with respect to the upper assembly;
(d) actuating the torque applicator to rotate the lower assembly with respect to the upper assembly to tighten the connection.
Where the wrench includes the spinner yieldably mounted on the upper assembly thereof, the spinning step preferably includes operation of the spinner.
In yet another aspect, the present invention provides an apparatus for coupling and decoupling downhole tools from a drill string on the rig floor. The apparatus has a plate providing a hole in the center having a non-circular geometric profile suitable for engagement of an exterior surface of the downhole tool. One or more arms extend upwardly from the plate for attaching the plate in spaced, torque-transmitting relationship below a hydraulically actuated wrench. The apparatus can also include a power wrench having brackets on a lower end thereof for attachment to the at least one upwardly extending arms of the hinged lockable plates, whereby torque may be applied to the drill string while holding the downhole tool in a relatively fixed position. The plate is preferably made of a pair of hinged, lockable sections that have opposing mating surfaces that form the geometric profile.